According to WCCFTech, Reddit user Hal_Nein_Thousand got his hands on another part of code of the PS3 version of GTA V, in which it is hinted that the PC version may have support for DX11 and 64 Bit memory.

Now the absolute first thing we noticed is the DX 11 tag in the code. This is unarguable, if the DX 11 Code is

Who cares, it's the optimisation that we're interested in. Pointless if it goes from 20 to 200fps can't be arsed with shitty stutter. Give me a steady consistent frame rate.
The avalanche 2 engine is superb at rendering distances with minuscule drop and zero lag.
GTA5, if it comes out on PC , will have many crying into their savings account for the gear that they will need to play this full on. Unless Rockstar turns out a miracle!_________________"Hackers and DRM are Turning Gaming into a Nightmarish Clusterfuck"